The present invention relates to a temperature detecting device. Such devices are sometimes used in a monitoring system for detecting abnormal events at an early stage by detecting a temperature of a fluid such as exhaust gas emitted from a device such as an engine. Such monitoring systems are effective in preventing failure of the device or accidents.
Japanese Patent Laying-Open No. 2004-157052 (Patent Document 1) describes an exemplary temperature sensor for detecting a temperature of a target fluid, wherein an element is provided in a distribution path in which the target fluid is distributed under a high temperature environment such as inside of a catalytic converter of an exhaust gas purifying device or inside of an exhaust pipe. Japanese Patent Laying-Open No. 2012-112710 (Patent Document 2) describes an exemplary temperature monitoring device.
In order to construct a system for monitoring the temperature of a fluid, temperature sensors are provided at a multiplicity of locations to form a sensor network. In the system disclosed in Patent Document I, temperature sensors which transmit the sensed temperatures to an external device do so using external wires. This limits the locations at which the sensors can be used and increases the costs of installation.
One possible solution to this problem is to use wireless temperature sensors. However, wireless temperature sensors needs a battery, resulting in a problem of replacement cost of the battery.
The device described in Patent Document 2, a thermoelectric conversion element is used to generate electric power based on heat energy received from a monitoring target, temperature information is generated based on a voltage signal output from the thermoelectric conversion element, and the temperature information is transmitted to outside through an antenna. However, Patent Document 2 provides no detailed description regarding application, method of contact to a heat source, a cooling method, and the like, and a specific structure thereof is unknown.
The present invention has an object to provide a temperature detecting device that preferably does not require wiring and battery exchange in order to secure power supply, that detects a temperature of a heat source, and that can operate continuously.